Automatic chromium plating apparatus



Dec. 19, 1967 KAZUYA HOJYO 3,359,195

AUTOMATIC CHROMIUM PLATING APPARATUS Filed Oct. 29, .1963

o g 0 I3 71 Am I A 3\ F X5 I4 X81") LIG 3 y W F v 1 INVENTOR KAZUYA HOJYO AT TORNEY.

United States Patent ABSTRACT OF THE DISCLOSURE An automatic chromium plating apparatus having a rotator in which an object to be plated is pressed, by centrifugal force created by rotation, against an annular cathode net where it is plated by ions emanating from adjacent positives which are arranged circumferentially to the cathode net.

The present invention relates to automatic apparatus for electroplating with chromium, in general, and to an apparatus for electroplating with chromium by the use of centrifugal force in order to closely press the object to be plated against an annular cathode net, on both circumferential sides of which are anodes that give forth positive ions to electroplate the object with chromium, in particular.

Because of the difficulty of attaining a uniform plating by any conventional chromium plating process, it has been hitherto necessary to put the object to be plated between a clip to hold it with the negative pole. But such a process completely requires manual work and is very inefficient.

It is one object of the present invention to provide an apparatus for chromium plating by which all such defects can be eliminated and by which a uniform chromium plating can be automatically attained extensively in a short time.

While this and other objects in view which will become apparent in the following detailed description, the present invention will be clearly understood in connection with the accompanying drawing, in which:

FIG. 1 illustrates a partly notched section of an apparatus in accordance with the present invention; and

FIG. 2 is an enlarged broken away section of the cathode net and showing the object to be plated.

Referring now to the drawing, and more particularly to FIG. 1, an apparatus in accordance with the present invention comprises a rotator 1 that has a hollow cylindrical shaft comprising a delivery route 2 in its central part, while its upper part is formed into a recessed conical portion 3 and on its top is fastened a circular or annular cathode net 4. Cylindrical inner and outer anode members or positives 5' and 5, respectively, revolve together with the rotator 1, upon the top of which is slidingly contacted an anode cable 6. An operating rod 7 has a plug valve 8 at its lower end adjacent the lower open apex of the cylindrical portion 3 and a member 9 supports the rotator 1. A pulley 10 is attached to the rotator, and an inlet 11 is provided about the rod 7. A catch 12 is arranged on the upper part of the cathode net 4 and an insulator 13 is provided for the outer anode member 5. A screw 14 is illustrated herein as an example of the object to be plated.

In operation of the apparatus in accordance with the present invention, a certain amount of the chromium plating liquid and the object 14 to be plated are placed into the rotator 1 through a conical funnel or inlet 11, as indicated by :arrow 16 showing the entrance path of an object 14 to be plated, while the upper part of the delivery route 2 is closed by the plug valve 8, as shown in FIGURE 1. In this condition, the rotator 1 will be net 4, respectively,

driven and caused to revolve by means of a pulley 10 connected with a motor (not illustrated). The working rod 7 will also revolve in conjunction with the rotator 1 and, through the centrifugal force caused by such rotation, the object 14, initially at lower part of the conical portion 3, will automatically move up the slope thereof and eventually reach the cathode net 4 that is arranged on the uppermost part of the conical portion 3, as indicated by arrow 17. Further advance of the object 14 is checked by the catch 12 which is provided on the upper end of the cathode net 4 and the object 14 is closely pressed against the lower or interior side of the net and is chromium plated by anode ions given forth by the positives 5' and 5 which are arranged one circumferentially inside and the other circumferentially outside the cathode standing cylindrically opposite to each other as shown by the arrow marks in the drawing. The working rod 7 will be lifted then to open the valve 8 in order to eject the object 14 downwardly through the delivery route 2, as indicated by arrow 18.

In order to get a better plating, however, a sporadic rotation may be given to the rotator 1, causing the object 14 to repeatedly go upward and downward three or four times along the slope of the conical portion 3, so that with the changing positions of its contact with the cathode net, a uniform and good chromium plating may be provided thereon. Besides, if the outer side of the cathode net 4 is covered by coating 15 as shown in FIG. 2 so that only the inner side will be exposed, the anions from the outwardly arranged positive 5, will pass outside the cathode net 4, as shown by the arrow marks, to directly reach its inner circumferential surface to provide an effective plating.

It should now be apparent that the present apparatus effectively utilizes centrifugal force to closely press an object to be plated against the cathode net whereby it is chromium plated by anode ions emanating from the positives which are arranged inside and outside the cathode net so as to stand opposite to each other.

According to the preferred embodiment, the cathode is provided between the inner and outer positives or anodes 5 and 5, respectively. But when the cathode is formed only outside the positive or anode 5', satisfactory results are similarly obtained.

While I have disclosed several embodiments of the present invention, it is to be understood that these embodiments are given by example only and not in a limit ing sense, the scope of the present invention being determined by the objects and the claims.

I claim:

1. An automatic chromium plating apparatus comprising a rotator means having a recessed conical portion widening toward a surface thereof and axially mounted for rotation,

said conical portion having an opening at its bottom apex,

a substantially annular disc cathode net axially disposed on the outer edge of the surface of said rotator means annularly and partly covering said recessed conical portion,

a cylindrical inner anode member axially disposed within said annular disc cathode net and perpendicular thereto, and

an operating rod axially disposed and axially movable within said cylindrical anode member.

2. The apparatus, as set forth in claim 1, further comprising a cylindrical outer anode member axially oriented about said annular disc cathode net.

3. The apparatus, as set forth in claim 2, wherein said cylindrical outer anode member is mounted on said surface of said rotator means spaced from said annular disc cathode net and mounted for rotation together with said rotator means, and

means for insulating said cylindrical outer anode member from said rotator means.

4. The apparatus, as set forth in claim 1, wherein said cylindrical inner anode member is adapted to rotate with said rotator means.

5. The apparatus, as set forth in claim 1, wherein said cylindrical inner anode member defines therein a passageway communicating with said recessed conical portion constituting an entrance passageway for a chromium plating liquid and an object to be plated.

6. The apparatus, as set forth in claim 5, further comprising a conical funnel member axially disposed relative to said cylindrical inner anode member and communicating with said entrance passageway.

7. The apparatus, as set forth in claim 5, further comprising said operating rod axially disposed and axially movable within said entrance passageway,

said operating rod extending through said entrance passageway into said recessed conical portion to a position adjacent the apex of said recessed conical portion,

said operating rod including a plug valve adjacent said apex of said recessed conical portion,

said rotator means defining said opening at the bottom of said apex of said recessed conical portion complementary to said plug valve,

said rotator means including a hollow cylindrical shaft communicating with said opening for removing plated objects therethrough, and said rotator means being substantially vertically disposed. 8. The apparatus, as set forth in claim 7, further comprising means for rotating said rotator means operatively connected axially to said hollow cylindrical shaft of said rotator means.

References Cited UNITED STATES PATENTS 1,481,311 1/1924 Appleton 204-213 X 1,858,125 5/1932 Von Devecis 204213 X 1,873,826 8/1932 Devecis 204213 2,016,446 10/1935 Merkenschlagen 2,04-2l3 2,085,711 6/1937 Bresmann 209-179 3,061,536 10/1962 Gruber 204-250 FOREIGN PATENTS 612,106 4/1935 Germany. 68,935 5/1926 Sweden.

JOHN H. MACK, Primary Examiner.

W. VAN SISE, Assistant Examiner. 

1. AN AUTOMATIC CHROMIUM PLATING APPARATUS COMPRISING A ROTATOR MEANS HAVING A RECESSED CONICAL PORTION WIDENING TOWARD A SURFACE THEREOF AND AXIALLY MOUNTED FOR ROTATION, SAID CONICAL PORTION HAVING AN OPENING AT ITS BOTTOM APEX, A SUBSTANTIALLY ANNULAR DISC CATHODE NET AXIALLY DISPOSED ON THE OUTER EDGE OF THE SURFACE OF SAID ROTATOR MEANS ANNULARLY AND PARTLY COVERING SAID RECESSED CONICAL PORTION, A CYLINDRICAL INNER ANODE MEMBER AXIALLY DISPOSED WITHIN SAID ANNULAR DISC CATHODE NET AND PERPENDICULAR THERETO, AND AN OPERATING ROD AXIALLY DISPOSED AND AXIALLY MOVABLE WITHIN SAID CYLINDRICAL ANODE MEMBER. 